51415990 has 24 divisors (see below), whose sum is σ = 98318592. Its totient is φ = 19355520.

The previous prime is 51415981. The next prime is 51415993. The reversal of 51415990 is 9951415.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51415993) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6006 + ... + 11785.

It is an arithmetic number, because the mean of its divisors is an integer number (4096608).

Almost surely, 2^51415990 is an apocalyptic number.

51415990 is a deficient number, since it is larger than the sum of its proper divisors (46902602).

51415990 is a wasteful number, since it uses less digits than its factorization.

51415990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17832 (or 17815 counting only the distinct ones).

The product of its (nonzero) digits is 8100, while the sum is 34.

The square root of 51415990 is about 7170.4944041537. The cubic root of 51415990 is about 371.8485287280.

The spelling of 51415990 in words is "fifty-one million, four hundred fifteen thousand, nine hundred ninety".